176,847 research outputs found

    Exclusive diffractive electroproduction of dijets in collinear factorization

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    Exclusive electroproduction of hard dijets can be described within the collinear factorization. This process has clear experimental signature and provides one with an interesting alternative venue to test QCD description of hard diffractive processes and extract information on generalized nucleon parton distributions. In this work we present detailed leading-order QCD calculations of the relevant cross sections, including longitudinal momentum fraction distribution of the dijets and their azimuthal angle dependence.Comment: 11 pages, 14 Postscript figures, uses revtex4.st

    Analysis of clustering phenomena in ab initio approaches

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    An approach for explicit consideration of cluster effects in nuclear systems and accurate ab initio calculations of cluster characteristics of nuclei is devised. The essential block of the approach is a construction of a basis which incorporates both conventional No-Core Shell Model wave functions and translationally-invariant wave functions of various cluster channels. The results of computations of the total binding energies of 8Be nucleus as well as the spectroscopic factors of cluster channels (amount of clustering) are presented. An unexpected fresh result of the rigorous study is that the contribution of "non-clustered" components of the basis to the total binding energy is great even in the typical cluster systems such as the discussed nucleus

    Description of bulk observables in Au+Au collisions at top RHIC energy in the integrated HydroKinetic Model

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    The results on the main bulk observables obtained in the simulations within the integrated hydrokinetic model (iHKM) of Au+Au collisions at the RHIC energy sNN=200\sqrt{s_{NN}}=200 GeV are presented along with the corresponding experimental data from the STAR and the PHENIX collaborations. The simulations include all the stages of the collision process: formation of the initial state, its gradual thermalization and hydrodynamization, viscous relativistic hydro-evolution, system's hadronization and particlization, and, finally, an expansion of the interacting hadron-resonance gas. The model gives a satisfactory description of charged-particle multiplicities, particle number ratios, transverse momentum spectra for pions, kaons, protons and antiprotons, charged-particle v2v_2 coefficients, and femtoscopy radii at all collision centralities. It is demonstrated how one can estimate the times of the pion and kaon maximal emission from the femto-scales.Comment: 17 pages, 14 figure

    Description of bulk observables in Au+Au collisions at top RHIC energy in the integrated HydroKinetic Model

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    The results on the main bulk observables obtained in the simulations within the integrated hydrokinetic model (iHKM) of Au+Au collisions at the RHIC energy sNN=200\sqrt{s_{NN}}=200 GeV are presented along with the corresponding experimental data from the STAR and the PHENIX collaborations. The simulations include all the stages of the collision process: formation of the initial state, its gradual thermalization and hydrodynamization, viscous relativistic hydro-evolution, system's hadronization and particlization, and, finally, an expansion of the interacting hadron-resonance gas. The model gives a satisfactory description of charged-particle multiplicities, particle number ratios, transverse momentum spectra for pions, kaons, protons and antiprotons, charged-particle v2v_2 coefficients, and femtoscopy radii at all collision centralities. It is demonstrated how one can estimate the times of the pion and kaon maximal emission from the femto-scales.Comment: 17 pages, 14 figure

    New critical behavior in unconventional ferromagnetic superconductors

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    New critical behavior in unconventional superconductors and superfluids is established and described by the Wilson-Fisher renormalization-group method. For certain ordering symmetries a new type of fluctuation-driven first order phase transitions at finite and zero temperature are predicted. The results can be applied to a wide class of ferromagnetic superconducting and superfluid systems, in particular, to itinerant ferromagnets as UGe2 and URhGe.Comment: 12 pages, 6 fig

    Gate-controlled superconductivity in diffusive multiwalled carbon nanotube

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    We have investigated electrical transport in a diffusive multiwalled carbon nanotube contacted using superconducting leads made of Al/Ti sandwich structure. We find proximity-induced superconductivity with measured critical currents up to I_cm = 1.3 nA, tunable by gate voltage down to 10 pA. The supercurrent branch displays a finite zero bias resistance which varies as R_0 proportional to I_cm^-alpha with alpha=0.74. Using IV-characteristics of junctions with phase diffusion, a good agreement is obtained with Josephson coupling energy in the long, diffusive junction model of A.D Zaikin and G.F. Zharkov (Sov. J. Low Temp. Phys. 7, 184 (1981)).Comment: 5 pages, 4 figure

    On the problem of catastrophic relaxation in superfluid 3-He-B

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    In this Letter we discussed the parametric instability of texture of homogeneous (in time) spin precession, explaining how spatial inhomogeneity of the texture may change the threshold of the instability in comparison with idealized spatial homogeneous case, considered in our JETP Letter \textbf{83}, 530 (2006), cond-mat/0605386. This discussion is inspired by critical Comment of I.A. Fomin (cond-mat/0606760) related to the above questions. In addition we considered here results of direct numerical simulations of the full Leggett-Takagi equation of motion for magnetization in superfluid 3He-B and experimental data for magnetic field dependence of the catastrophic relaxation, that provide solid support of the theory of this phenomenon, presented in our 2006 JETP Letter.Comment: 5 pages, 1 fig. included, JETP Lett. style, submitted to JETP Lett. as response to Comment cond-mat/060676

    Stripping Cross Sections in Collisions of Light Nuclei

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    By evaluating all the contributions of the intermediate states of the multiple scattering theory diagrams, we compute the integrated stripping cross sections of collisions among light nuclei. The resulting expressions have the simple form of a combination of total inelastic cross sections of nuclear reactions with projectile nuclei differing in the atomic mass number. We also check the accuracy of some widely used relations in heavy ion collisions.Comment: 9 pages, 4 figures, Latex fil

    The c-axis charge traveling wave in coupled system of Josephson junctions

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    We demonstrate a manifestation of the charge traveling wave along the c-axis (TW) in current voltage characteristics of coupled Josephson junctions in high-TcT_c superconductors. The branches related to the TW with different wavelengths are found for the stacks with different number of Josephson junctions at different values of system's parameters. Transitions between the TW branches and the outermost branch are observed. Time dependence of the electric charge in the superconducting layers and charge-charge correlation functions for TW and outermost branches show different behavior with bias current. We propose an experimental testing of the TW by microwave irradiation.Comment: Supplement : http://theor.jinr.ru/~hamdipur/lambda0.av
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